Sightings of unusual jellyfish in the Great Lakes

What's believed to be the first photograph of a live Desmonema scoresbyanna jellyfish in Australian waters was taken off Tuncurry's breakwall by Forster's Vicki Stewart.

It was an unexpectedly rare sighting, unknowingly captured by Forster’s Vicki Stewart near Tuncurry’s breakwall earlier this month, which got marine experts excited.

In fact, the scientifically relevant finding of a rare Desmonema jellyfish in Australian waters – Forster’s waters, no less – gives proof to the old adage ‘if in doubt, ask’.

Now thanks to Vicki’s photograph of the lone jelly fish taken on October 7, Vicki has unknowingly provided marine experts with their first live image of a Desmonema in Australian waters - a rare sighting apparently.

The Advocate contacted collection manager Dr Stephen Keable at the Australian Museum Research Institute, who in turn passed it onto his colleague Dr Gershwin. She identified it as most likely a Desmonema scoresbyanna – a temperate water stinger she named and classified in 2008 based on three museum specimens as nothing live was available (she has named 199 species of jellyfish, and one dolphin).

“I've never seen it live or even seen a photo of it live (until now),” she said.

“I think it's the same one. I would only be able to tell by fine-scale characters, but it looks exactly like I would expect it to look!”

Further comments refer to the identifying tentacles in clusters as straight lines. Dr Gershwin added that Vicki’s image was the only photo she knew of showing Desmonema in Australian waters, “so perhaps if people know what it looks like and how special it is, more reports will emerge.”

”Every sighting helps us,” she said, referring to how little is known about the species.

With a safety and identification app for jellyfish of the world about to be released, she said that findings such as this are great to show the “important role museums play as a focus point for sightings like this.” She now hopes to add Vicki’s photo to the app.

“Wow, what a really splendid find! Soooo excited!” she said.

Vicki responded that it was a lovely clear sunny morning when she took the photo of the jellyfish.

“The jellyfish was by itself on the Tuncurry side of the breakwall, close in to the rocks, and just a few meters past the netting protecting the Tuncurry Rockpool. Behaviour-wise, it was doing pretty much what most jellyfish do, floating along with the tide with the occasional course correction.”

Interested in obtaining a specimen for the museum, Dr Keable said that “if it is in the Wallis Lake area it would be the second unusual jellyfish to turn up there recently.”

He cited the discovery of the Cassiopea jellyfish – commonly known as upside-down jellyfish - in Wallis Lake over recent consecutive seasons (they were also found in Lake Illawarra). The Cassiopea is normally found in tropical climates and these are the first records of its presence in temperate eastern Australian waters.

“The sudden appearance of these jellyfish in large numbers (blooms) is significant. Elsewhere, some jellyfish, including species of Cassiopea, are considered invasive. These jellyfish have the potential to act negatively on the local marine environment, in addition to impacting the public and commercial use of waterways when congregating in large numbers,” he blogged in June on the Museum’s website.

“The two new localities represent southern range extensions of the genus by approximately 600 km to 900 km from previously known locations in southern Queensland.”

Due to the recreational nature of Wallis Lake, he attributed the Cassiopea’s appearance less likely to normal environmental variations “driving changes in species’ ranges” but more to human influences, such as shipping and intentional or unintentional release, with subsequent consequences.

He hopes to ultimately track local changes in the jellyfish’ ‘bloom and bust’ population through a citizen science project, using the surveillance of local residents.

Care must be taken when handling jellyfish to avoid being stung. Suspected Desmonema specimens must be frozen. Photos welcome. More information at www.stingeradvisor.com

Cassiopea cf. maremetens lying on sand in upside-down position. This normally tropical jellyfish is now being seen in Wallis Lake in varying numbers.
Photographer: Stephen Keable, courtesy of Australian Museum